Security is the most sensible subject in today’s contemporary scenarios. It can be real world or cyber world. In the cyber world, an attack is introduced with the gathering of information. The computer network is used widely in today’s world with wide computerization and expansion.

The software and information are more vulnerable to get disturbed by the unauthorized users because of the interlinked computers over computer networks.

The minicomputers and mainframe computers are being replaced by the network of computer. With the migration to network computers, the issue of security has increased. It is requisite to have the basic knowledge of computer networks to understand the network security principles. The network assets are protected by network security.

There are various threats to the network security of networks and computers. They are Data Stealing, Data Diddling, Hackers, Viruses, and Loss of Data.

The services to secure the network from attacks are confidentiality, authentication, integrity, non-repudiation, access control, and availability. Network security attacks are classified into passive and active attacks.

Firewalls secure the network systems or local system from threats of network security and it is a set of components between two networks to form a barrier. The kinds of firewalls are application gateways, packet filtering, and hybrid systems.

Conclusion:

The project concludes on the network security, threats and firewalls with implementation of security services. The mechanisms of security depend on algorithms of cryptographic such asymmetric-RSA, symmetric-DES, AES, and ECC. These algorithms are used to obtain security levels and optimal speed.